Gene Ulm from Public Opinion Strategies said Clinton's gain was most likely due to the first presidential debate and Trump's reaction to the debate.

The WTHR/HPI Indiana Poll also investigated the reasons for support of both main candidates and found a similar story for both Trump and Clinton. The poll asked respondents if they were voting for Trump or Clinton because they support that candidate or if they were reluctantly voting for them because they can't vote for their opposition. The poll found 43% of Trump supporters were voting for Trump because they can't support Clinton and 35% of Clinton supporters were voting for her because they can't support Trump.

The WTHR/HPI Indiana Poll asked which candidate would perform better in four different areas. Trump performed better with "protecting Americans from terror" 45% to Clinton's 32% and "improve job and the economic situation" by a score of 49% to Clinton's 33%. Clinton received high marks for "improve race relations" with a 46% to 23% edge. The two had a closer score for "do better on immigration" with Trump edging out Clinton 42% to 38%.

A noteworthy change since the September WTHR/HPI Indiana Poll in the demographic breakdown is along party lines. Trump lost 4-points of support with members of the GOP while Clinton saw gains of 8-points with independents and 7-points with democrats.

The poll found the favorability of both main candidates has shifted slightly since earlier polls. Clinton has improved her net favorability from -31 in April to -29 in September to -25 in the new October poll. Trump's net favorability slipped from -12 in September to -15 in October.

Clinton made the biggest net favorability gains from September's poll with independents, changing from -52 to -27. Trump slipped in independents from a -10 to a -27. Trump's net favorability dropped from a -44 to a -64 with minority voters.

WTHR commissioned the poll with Howey Politics Indiana. The Public Opinion Strategies poll surveyed 600 likely voters in the state from October 3-5. It has a four-point margin of error.